Lightning-arrester



(No Model.)

J. W. GIBBONEY. LIGHTNING ARRESTER.

No. 520,776. Patented June 5, 1894.

UNITED STATES PATENT OFFICE.

JOHN \V. GIBBONEY, OF LYNN, ASSIGNOR TO'THE GENERAL ELECTRIC COM- PANY,OF BOSTON, MASSACHUSETTS.

LlGHTNlNG-ARRESTER.

SPECIFICATION forming part of Letters Patent No. 520,776, dated June 5,1894.

Application filed February 6,1893- Serial No. 461,176 (No model.

To all whom it may concern.-

Be it known that 1, JOHN W. GIBBONEY, a citizen of the United States,residing at Lynn, county of Essex, and State of Massachusetts, haveinvented certain new and useful Improvements in Lightning-Arresters, ofwhich the following is a specification.

My invention relates to devices for protecting electric circuits frominjurious or destructive static discharges. Its especial object is torelieve the work circuit of a dynamo electric machine from the danger ofa short circuit which may be established by a static discharge of highpotential. A further object is to thoroughly protect the generator fromheavy disruptive discharges.

The invention consists in a constantly maintained short circuit ofsufficiently high resistance to prevent any leakage of the workingcurrent, but permitting free passage to static charges. In connectiontherewith I prefer to use a spark gap lightning arrester to carry offheavy static charges which would be liable to injure the generator andmight not be readily conveyed away by the constantly maintained shortcircuit.

The medium which I prefer to use for the constantly maintained shortcircuit is a liquid, such as acidulated water, and it is kept flowingfrom one main-line conductor to the other by any suitable means, so asto present a constant path for the static discharges. It is, moreover,indestructible, being constantly renewed from the source of supply. Itis therefore always ready for action, and requires no resetting orattention.

The invention is applicable to either continuous current or alternatingcurrent systems.

The accompanying drawings illustrate two modes of applying it to acontinuous current railway system.

Figure 1 shows an apparatus in which the liquid flows by gravity from anupper to a lower reservoir. Fig. 2 shows an apparatus in which theliquid is forcibly projected against a spray plate, whence it falls intoa receptacle.

Let A represent a generator of continuous currents and B B the twomain-line conductors supplying current to the translating devices, suchas railway motors C. One main,

as B, is connected to a metallic spray p1ate D, below which is areceptacle E connected with the other main and with the earth. Means are5 5 provided for discharging upon the spray plate a supply of acidulatedwater. This may consist of a pump F drawing water from a suitablesource, such as the receptacle E, and delivering it either into an upperreservoir G, from which it overflows upon the plate D, as

in Fig. 1, or directly against the spray plate from a nozzle, as in Fig.2. In either case, the water flows in fine streams or drops across thespace between the mains B B, forming a constant short circuit, but ofsuch high resistance as to practically prevent any leakage of thegenerator current, though offering no obstacle to the passage of staticcharges of high potential. This short circuit therefore prov des aconstantly maintained means for establishrn g an equilibrium between themains B with respect to charges of abnormally high potential.

Lest this device should not be capable of carrying off very heavydisruptive discharges, which might flow through the generator andseriously injure or even ruin it, I prefer to use also a spark gaplightning arrester H, preferably one having an arc rupturing device,such for instance as is shown in the patent to Wood, No. 460,289. Bythus combining these two arresters, I thoroughly protect the line andthe apparatus from static discharges, both small and quiet ones, andthose which are heavy and sudden.

What I claim as new, and desire to secure by Letters Patent, is-

1. The combination with an electric generator and awork circuit suppliedtherefrom, of a constantly maintained short circu t composed of liquidflowing from one ma n-hue conductor to the other, substantially asdescribed.

2. The combination with an electric generator and a work circuitsupplied therefrom, of aconstantly maintained short circuit composed ofliquid flowing in fine streams or drops from one main-line conductor tothe other, substantially as set forth. I

3. The combination with an electric generator and a work circuitsupplied therefrom, of a spray plate connected with one main-lineconductor, a grounded receptacle connected with the other conductorbelow the spray plate, and means for conveying liquid to the of aconstantly maintained short circuit of high resistance, and a spark gaplightning arrester, both connected across the main line conductor and toground, substantially as described.

In Witness whereof I have hereunto set my hand this 2d day of February,1893.

JOHN W. GIBBONEY.

Witnesses:

BENJAMIN B. HULL, J OHN T. BRODERIGK.

